Hey, new to the forum and I have an 88 Mighty Max with the 2.6 and KM145 transmission. It's getting a little hard to get into gear and I an going to change the fluid. I've read on a post here to use GL5 rated fluid. I am between Redline MT-90, Redline 75W-90, and Pennzoil Synchromesh. Any advise would be greatly appreciated!